Pagliari Anderson B, Orlando Tainára, Salbego Paulo R S, Zimmer Geórgia C, Hörner Manfredo, Zanatta Nilo, Bonacorso Helio G, Martins Marcos A P
Núcleo de Química de Heterociclos (NUQUIMHE) and Núcleo de Investigação de Triazenos e Complexos (NITRICO), Department of Chemistry, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, Rio Grande do Sul, Brazil.
ACS Omega. 2018 Oct 22;3(10):13850-13861. doi: 10.1021/acsomega.8b01801. eCollection 2018 Oct 31.
A series of seven -phenylamides [R-C(O)NHPh, in which R: CH, C(CH), Ph, CF, CCl, CBr, and H] were used as models in this study. Molecular packing and intermolecular interactions were evaluated by theoretical calculations, solution NMR, and quantum theory of atoms in molecules analyses. Crystallization mechanisms were proposed based on the energetic and topological parameters using the supramolecular cluster as demarcation. Concentration-dependent H NMR experiments corroborated the proposed interactions between molecules. For all compounds (except for R: H, which initially formed tetramers), layers (two-dimensional) or chains (one-dimensional) were formed in the first stage of the proposed crystallization mechanisms. The presence of strong intermolecular NH···O=C interactions promoted the first stages. The study in solution provided different values of association constant ( ) governed by the hydrogen bond NH···O=C, showing that the stronger interactions are directly influenced by the substituent steric hindrance. A correlation between from the solution and the NH···O=C interaction energy in the crystal showed a good trend.
本研究使用了一系列七种苯酰胺[R-C(O)NHPh，其中R为：CH、C(CH)、Ph、CF、CCl、CBr和H]作为模型。通过理论计算、溶液核磁共振和分子中原子的量子理论分析来评估分子堆积和分子间相互作用。基于以超分子簇为界的能量和拓扑参数提出了结晶机制。浓度依赖性的¹H NMR实验证实了所提出的分子间相互作用。对于所有化合物（R为H的除外，其最初形成四聚体），在所提出的结晶机制的第一阶段形成了层（二维）或链（一维）。强分子间NH···O=C相互作用的存在促进了第一阶段。溶液中的研究提供了由氢键NH···O=C控制的不同缔合常数（ ）值，表明较强的相互作用直接受取代基空间位阻的影响。溶液中的 与晶体中NH···O=C相互作用能之间的相关性呈现出良好的趋势。
